odbc num_rows codeigniter result_set is empty
You can't just use the development version of CI_DB_odbc_result and keep the rest of the stuff from the 2.1 version tree. If you don't want to replace all of them, what you need to get from the repository are the following files:
system/database/DB_driver.phpsystem/database/DB_result.phpsystem/database/drivers/odbc/odbc_driver.phpsystem/database/drivers/odbc/odbc_result.php(assuming that you only use ODBC)
There still could be an issue with the ODBC result class and I'll look into that, but considering that your question refers to a yet unreleased version of CodeIgniter - it would be better that you post any problem reports to either the CodeIgniter forums or the GitHub repository.
There is an error in the if condition, use:
$q->num_rows()and try to use
$q->result() instead ->row()